Module: JsonLogging

Defined in:
lib/json_logging.rb,
lib/json_logging/helpers.rb,
lib/json_logging/version.rb,
lib/json_logging/formatter.rb,
lib/json_logging/sanitizer.rb,
lib/json_logging/json_logger.rb,
lib/json_logging/message_parser.rb,
lib/json_logging/payload_builder.rb,
lib/json_logging/formatter_with_tags.rb,
lib/activesupport/json_logging/railtie.rb,
lib/json_logging/json_logger_extension.rb

Defined Under Namespace

Modules: Helpers, JsonLoggerExtension, LocalTagStorage, MessageParser, PayloadBuilder, Sanitizer Classes: Formatter, FormatterWithTags, JsonLogger, Railtie

Constant Summary collapse

THREAD_CONTEXT_KEY = 
:__json_logging_context
VERSION = 
"1.2.0"

Class Method Summary collapse

Class Method Details

.additional_context(*args, &block) ⇒ Object

Returns the current thread-local context when called without arguments, or sets a transformer when called with a block or assigned a proc.

Examples:

Getting context

JsonLogging.additional_context  # => {user_id: 123, ...}

Setting transformer with block

JsonLogging.additional_context do |context|
  context.merge(environment: Rails.env, hostname: Socket.gethostname)
end

Setting transformer with assignment

JsonLogging.additional_context = ->(context) { context.merge(env: Rails.env) }


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# File 'lib/json_logging.rb', line 39

def self.additional_context(*args, &block)
  if args.any? || block_given?
    return public_send(:additional_context=, args.first || block)
  end

  begin
    base_context = (Thread.current[THREAD_CONTEXT_KEY] || {}).dup
  rescue
    base_context = {}
  end

  transformer = @additional_context_transformer
  if transformer.is_a?(Proc)
    begin
      transformer.call(base_context)
    rescue
      base_context
    end
  else
    base_context
  end
end

.additional_context=(proc_or_block) ⇒ Object 



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# File 'lib/json_logging.rb', line 62

def self.additional_context=(proc_or_block)
  @additional_context_transformer = proc_or_block
end

.logger(*args, **kwargs) ⇒ Logger

Returns an ‘ActiveSupport::Logger` that has already been wrapped with JSON logging concern.

Examples:

logger = JsonLogging.logger($stdout)
logger.info("Stuff")  # Logs JSON formatted entry

Parameters:

  • *args —

    Arguments passed to ActiveSupport::Logger.new

  • **kwargs —

    Keyword arguments passed to ActiveSupport::Logger.new

Returns:

  • (Logger) —

    A logger wrapped with JSON formatting and tagged logging support



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# File 'lib/json_logging.rb', line 81

def self.logger(*args, **kwargs)
  new(ActiveSupport::Logger.new(*args, **kwargs))
end

.new(logger) ⇒ Logger

Wraps any standard Logger object to provide JSON formatting capabilities. Similar to ActiveSupport::TaggedLogging.new

Examples:

logger = JsonLogging.new(Logger.new(STDOUT))
logger.info("Stuff")  # Logs JSON formatted entry

With tagged logging

logger = JsonLogging.new(Logger.new(STDOUT))
logger.tagged("BCX") { logger.info("Stuff") }  # Logs with tags
logger.tagged("BCX").info("Stuff")  # Logs with tags (non-block form)

Parameters:

  • logger (Logger) —

    Any standard Logger object (Logger, ActiveSupport::Logger, etc.)

Returns:

  • (Logger) —

    A logger extended with JSON formatting and tagged logging support



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# File 'lib/json_logging.rb', line 99

def self.new(logger)
  logger = logger.clone
  if logger.formatter
    logger.formatter = logger.formatter.clone

    # Workaround for https://bugs.ruby-lang.org/issues/20250
    # Can be removed when Ruby 3.4 is the least supported version.
    logger.formatter.object_id if logger.formatter.is_a?(Proc)
  else
    # Ensure we set a default formatter so we aren't extending nil!
    # Use ActiveSupport::Logger::SimpleFormatter if available, otherwise default Logger::Formatter
    logger.formatter = if defined?(ActiveSupport::Logger::SimpleFormatter)
      ActiveSupport::Logger::SimpleFormatter.new
    else
      ::Logger::Formatter.new
    end
  end

  logger.extend(JsonLoggerExtension)
  formatter_with_tags = FormatterWithTags.new(logger)
  logger.instance_variable_set(:@formatter_with_tags, formatter_with_tags)
  logger.formatter = formatter_with_tags

  logger
end

.safe_hash(obj) ⇒ Object 



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# File 'lib/json_logging.rb', line 66

def self.safe_hash(obj)
  obj.is_a?(Hash) ? obj : {}
rescue
  {}
end

.with_context(extra_context) ⇒ Object 



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# File 'lib/json_logging.rb', line 18

def self.with_context(extra_context)
  original = Thread.current[THREAD_CONTEXT_KEY]
  Thread.current[THREAD_CONTEXT_KEY] = (original || {}).merge(safe_hash(extra_context))
  yield
ensure
  Thread.current[THREAD_CONTEXT_KEY] = original
end